Which 100cm long and 2.0 mm diameter has a resistance of 0.7 ohm, the electrical resistivity of the material is

Explanation

The resistance R of a wire is given by the formula R = ρ * (L/A), where ρ is the resistivity, L is the length, and A is the cross-sectional area.First, convert the length from cm to meters: L = 100 cm = 1.0 m.The diameter of the wire is 2.0 mm, so the radius r = 1.0 mm = 0.001 m. The cross-sectional area A = πr² = π(0.001 m)² = 3.14 × 10-6 m².Substitute the known values into the formula to solve for ρ: ρ = R * (A/L) = 0.7 ohm * (3.14 × 10-6 m² / 1.0 m) = 2.198 × 10-6 ohm m, which rounds to 2.2 × 10-6 ohm m.Therefore, the correct answer is Option C, 2.2 × 10-6 ohm m. Other options are incorrect due to errors in calculation or unit conversion.